Gov. Andrew Cuomo has declared a public health emergency for the entire state in response to the spreading flu. The order allows pharmacists to administer flu vaccinations to children 6 months and older.

The move on Saturday comes as the number of patients admitted to hospitals throughout the state with confirmed cases of influenza spiked 55 percent last week. Two children have also died, according to the state Health Department.

Cuomo called it "the worst flu season since at least 2009," and said all New Yorkers should have access to "critically needed flu vaccines."

The executive order suspends the section of state law that limits pharmacists to administer immunizations to people 18 and older.

New Yorkers can find flu vaccine providers here, or by calling 800-522-5006.

Mirroring a wave of illness throughout 47 states, data show incidence of the flu has been widespread throughout New York for seven weeks. Doctors say flu season started early this season.

Already 19,128 cases of influenza have been reported throughout the state this season, compared to 4,404 during all of last season. There have also been 2,884 people hospitalized as of Jan. 5, compared to 1,169 total hospitalizations in 2011.

Nearly 7 percent of all visits to health care providers were flu or flu-like illnesses in the first week of the year, compared with a typical 2 percent, Health Department figures show.

"It's a really bad year," said Dr. Ken Steier, a lung specialist and clinical dean at Touro College of Osteopathic Medicine, who estimated he's seeing five times as many cases as is typical for this time of year. "It's really been knocking people out."

And it's likely to spread more, said Dr. Paul Hamlin, a pulmonary disease specialist based on Long Island. "I would expect to see more of it in the next four weeks," he said.

Typically, cases peak and then taper off, but it's hard to predict if this is a normal cycle or the outbreak will last through late March, when the seasonal illness usually falls off.

One reason for that is that the flu is highly contagious. An uncovered sneeze in a crowded subway car or a sick colleague who refuses to stay home from work can spread the illness quickly.

"The risk of getting the flu is definitely increased when you're in close contact with strangers," said Steier. And even those who stay home until they feel better can spread the virus, he added. "You're actually still contagious after you feel better."

Steier said the incubation period — the time between first exposure and when symptoms develop — can be up to seven days. The worst symptoms usually pass in a few days, but it's still possible to pass it along up to 14 days later.

Many people can treat their symptoms with rest, chicken soup or other fluids, and aspirin or Tylenol. But those with severe symptoms should contact their doctors.

Kate Allan, 16, said three days of exhaustion and achiness drove her to visit an Urgent Care facility in Manhattan on Friday, despite the fact that she has had a flu shot.

"My mom said it might not be the flu but my dad is really sick and my brother just had the flu, but he didn't have a flu shot," she said. "We weren't really sure what it is so we came in here today."

Allan's flu test came back negative, so Dr. Neal Shipley sent her home with Tylenol.

"The flu doesn't care if you're a man or a woman, old or young. It just wants to know if you've been vaccinated or not," he said.

Emergency room visits for the flu have jumped along with reported cases overall. Dr. Dan Wiener, the chairman of emergency medicine at Saint Luke's Roosevelt Hospital, said the increase is stressing capacity at the Manhattan hospital, which like several other facilities was already taking on a greater role to compensate for hospitals closed or damaged by Sandy.

But Wiener said it makes sense to stay out of the emergency room unless you're in a high risk group, like the elderly, or experiencing very serious symptoms like a persistent high fever. "Unless you're in a high risk group, there's not much we can do," he said.

Still, it's a serious illness. At least 10 residents of long-term care facilities like nursing homes have died in New York City. City nursing homes are seeing an epidemic, Wiener said, noting that people who are already ill or weak before contracting the flu are more vulnerable.

Doctors have mixed opinions about whether this year's flu is more severe than past years, or if it just spread faster. But all agree that for those who haven't been sick yet, it makes sense to get a flu vaccine. Each year's vaccine is designed to combat a different strain of the virus, and this year's shot was successful in targeting the most prevalent strain.

The vaccine will help about 70 percent of people who get it avoid the illness altogether, and the remaining 30 percent will likely have a milder case.

And Steier said don't worry about getting the flu from the shot itself. "That's not possible," he said. "It's basically a killed virus."